Industrial metabolic engineering is a method for performing strain improvement in industrial microorganisms by harnessing the power of random in vitro transposition mutagenesis. The organisms we aim to improve in this study are the actinomycetes, a group of soil bacteria that are best known for their ability to produce over two thirds of the worlds naturally derived antibiotics, anticancer agents, and immunosuppressants currently in medical use. The transposon tagging process is powerful not only because of its ability to make strain improvement mutations, but also because it allows strains to be easily reverse engineered to reveal the identity of the affected gene. Once the strain improvement target is identified, new genetic and metabolic knowledge is revealed that can lead to further optimization and extension of the technology to other organisms of medical importance. The model organism used in this study is the erythromycin producing organism, Saccharopolyspora erythraea, a bacterium that has been the subject of over 50 years of intensive genetic and biochemical research, providing a solid foundation upon which to build the fundamentals for the emerging field of metabolic engineering of industrial microorganisms. [unreadable] [unreadable] [unreadable]